scholarly journals Bödewadt Flow Over a Permeable Disk with Homogeneous-Heterogeneous Reactions: A Numerical Study

2019 ◽  
Vol 9 (19) ◽  
pp. 4046 ◽  
Author(s):  
Talat Rafiq ◽  
Meraj Mustafa Hashmi
Keyword(s):  
Chemical Reaction ◽  
Numerical Study ◽  
Exact Formula ◽  
Heterogeneous Reactions ◽  
Concentration Boundary ◽  
First Order Kinetics ◽  
Mass Transfer Parameter ◽  
Bulk Reaction ◽  
Self Similar ◽  
Cubic Autocatalator

We analyzed the onset of homogeneous-heterogeneous reactions in Bödewadt flow occurring over an isothermal and permeable surface. This research is based on the assumption that the homogeneous (bulk) reaction follows isothermal cubic autocatalator kinetics, whereas the surface reaction is governed by first-order kinetics. The heat energy released during the chemical reaction is assumed to be negligible. The governing equations are reducible to a set of self-similar equations, which are handled numerically. Asymptotic analysis was conducted, which revealed that the existence of a concentration boundary layer on the disk is possible only when the disk is subjected to a sufficient amount of suction. In a large suction situation, an exact formula for concentration profile ϕ was derived that strongly supports the obtained numerical solution. Our results demonstrate the mass transfer parameter considerably alters flow fields. The concentration at the wall varies substantially when the chemical reaction proceeds at a faster rate.

scholarly journals Homogeneous–Heterogeneous Reactions in Boundary-Layer Flow of a Nanofluid Near the Forward Stagnation Point of a Cylinder

2016 ◽  
Vol 139 (3) ◽  
Author(s):  
Qingkai Zhao ◽  
Hang Xu ◽  
Longbin Tao
Keyword(s):  
Stagnation Point ◽  
Diffusion Coefficients ◽  
Multiple Solutions ◽  
Heterogeneous Reaction ◽  
Heterogeneous Reactions ◽  
Homogeneous Reaction ◽  
First Order ◽  
First Order Kinetics ◽  
Layer Flow ◽  
Cubic Autocatalator

A mathematical model describing the homogeneous–heterogeneous reactions in the vicinity of the forward stagnation point of a cylinder immerged in a nanofluid is established. We assume that the homogeneous reaction is given by isothermal cubic autocatalator kinetics, while the heterogeneous reaction is chosen as first-order kinetics. The existence of multiple solutions through hysteresis bifurcations is discussed in detail for the various diffusion coefficients of reactant and autocatalyst.

Two-dimensional numerical study of temperature field in an anode supported planar SOFC: Effect of the chemical reaction

2011 ◽  
Vol 36 (6) ◽  
pp. 4228-4235 ◽  
Author(s):  
Bariza Zitouni ◽  
G.M. Andreadis ◽  
Ben Moussa Hocine ◽  
Abdenebi Hafsia ◽  
Haddad Djamel ◽  
...  
Keyword(s):  
Temperature Field ◽  
Chemical Reaction ◽  
Numerical Study ◽  
Two Dimensional

scholarly journals A Numerical Study of Chemical Reaction in a Nanofluid Flow Due to Rotating Disk in the Presence of Magnetic Field

2021 ◽  
Author(s):  
Muhammad Ramzan ◽  
Poom Kumam ◽  
Kottakkaran Sooppy Nisar ◽  
Ilyas Khan ◽  
Wasim Jamshed
Keyword(s):  
Differential Equation ◽  
Radial Velocity ◽  
Chemical Reaction ◽  
Axial Velocity ◽  
Numerical Study ◽  
Tangential Velocity ◽  
Rotating Disk ◽  
Partial Differential ◽  
Suction Parameter ◽  
Matlab Programming

Abstract In this paper, a numerical study of MHD steady flow due to the rotating disk with chemical reaction was explored. Effect of different parameters such as Schmidt number, chemical reaction parameter, Prandtl number, Suction parameter, heat absorption/generation parameter, Nano-particle concentration, Reynold number, Magnetic parameter, skin friction, shear stress, temperature distribution, Nusselt number, mass transfer rate, radial velocity, axial velocity, and tangential velocity was analyzed and discussed. For the simplification of non-linear partial differential equations (PDEs) into the nonlinear ordinary differential equation (ODEs), the method of Similarity transformation was employed, and the resulting partial differential equation was solved by using finite difference method through MATLAB programming. This work's remarkable finding is that with the expansion of nanoparticle concentration radial velocity, tangential velocity and temperature of the fluid was enhanced but reverse reaction for axial velocity. Furthermore, the present results are found to be in excellent agreement with previously published work.

scholarly journals Cumulative Impact of Micropolar Fluid and Porosity on MHD Channel Flow: A Numerical Study

Coatings ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 93
Author(s):  
Kottakkaran Sooppy Nisar ◽  
Aftab Ahmed Faridi ◽  
Sohail Ahmad ◽  
Nargis Khan ◽  
Kashif Ali ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Chemical Reaction ◽  
Micropolar Fluid ◽  
Numerical Study ◽  
Nonlinear Differential Equations ◽  
X Rays ◽  
Cumulative Impact ◽  
Transfer Rates ◽  
Mass And Heat Transfer ◽  
The Impact

The mass and heat transfer magnetohydrodynamic (MHD) flows have a substantial use in heat exchangers, electromagnetic casting, X-rays, the cooling of nuclear reactors, mass transportation, magnetic drug treatment, energy systems, fiber coating, etc. The present work numerically explores the mass and heat transportation flow of MHD micropolar fluid with the consideration of a chemical reaction. The flow is taken between the walls of a permeable channel. The quasi-linearization technique is utilized to solve the complex dynamical coupled and nonlinear differential equations. The consequences of the preeminent parameters are portrayed via graphs and tables. A tabular and graphical comparison evidently reveals a correlation of our results with the existing ones. A strong deceleration is found in the concentration due to the effect of a chemical reaction. Furthermore, the impact of the magnetic field force is to devaluate the mass and heat transfer rates not only at the lower but at the upper channel walls, likewise.

Numerical Study of MHD Viscoelastic Fluid Flow with Binary Chemical Reaction and Arrhenius Activation Energy

2017 ◽  
Vol 15 (1) ◽  
Author(s):  
M. Mustafa ◽  
A. Mushtaq ◽  
T. Hayat ◽  
A. Alsaedi
Keyword(s):  
Activation Energy ◽  
Fluid Flow ◽  
Chemical Reaction ◽  
Viscoelastic Fluid ◽  
Numerical Study ◽  
Fluid Model ◽  
Constitutive Relations ◽  
Mathematical Formulation ◽  
Large Temperature ◽  
Temperature Function

Abstract Here we address the influence of heat/mass transfer on MHD axisymmetric viscoelastic fluid flow developed by an elastic sheet stretching linearly in the radial direction. Constitutive relations of Maxwell fluid model are utilized in mathematical formulation of the problem. Non-linear radiation heat flux is factored in the model which accounts for both small and large temperature differences. Chemical reaction effects with modified Arrhenius energy function are analyzed which are not yet explored for viscoelastic fluid flows. Highly accurate numerical computations are performed. Our computations show S-shaped profiles of temperature function in case of sufficiently large temperature differences. Species concentration increases when activation energy for chemical reaction is increased. However, both chemical reaction rate and temperature gradient tend to reduce the solute concentration.

On the Axisymmetric Vortex Flow Over a Flat Surface

1969 ◽  
Vol 36 (3) ◽  
pp. 614-619 ◽  
Author(s):  
E. W. Schwiderski
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Critical Reynolds Number ◽  
Numerical Study ◽  
Lower Boundary ◽  
Tangential Velocity ◽  
Slow Motion ◽  
Boundary Layer Separation ◽  
Local Boundary ◽  
Self Similar

The numerical study of the interaction of a potential vortex with a stationary surface recently published by Kidd and Farris [1] is extended through a transformation of the boundary-value problem to Volterra integral equations. The new calculations verified the results by Kidd and Farris and improved the bounds of the critical Reynolds number Nc, beyond which no self-similar vortex flows exist, to 5.5 < Nc < 5.6 The breakdown of the self-similar motions develops through an instability in the lower boundary layer, which is indicated by two inflection points in the tangential velocity profile. At the critical Reynolds number the lower inflection point reaches the surface and indicates the beginning of boundary-layer separation in the wake-type flow. If the Stokes linearization is applied, one arrives at a new Stokes paradox. However, this “paradox” can be resolved by correcting the free-stream pressure distortion of the Stokes approximation. The new slow-motion approximation is nonlinear and yields an integral which is also free of the Whitehead paradox. The properties of the new exact solution confirm the novel flow features previously detected in almost self-similar motions, which were constructed by adjustable local boundary-layer approximations.

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